Water-soluble pouches usually contain powdered or dry product ingredients that effectively dissolve in water or other liquids in order to function properly. Recently, a way to combine a water-soluble pouch with both a concentrated, dry-powdered detergent and a liquid grease cutter in a single, water-soluble package has been developed as exemplified by Procter & Gamble's CASCADE 2-in-1 ACTIONPACS™.
Introduced in August, 2003, the mini dual-compartmented packets for automatic dishwashing detergent are made with a water-soluble film rollstock from MonoSol LLC (www.monosol.com). The cold-water-soluble film packets 10 hold concentrated, powdered CASCADE brand automatic dishwasher detergent in one compartment 11 and blue, liquid DAWN® grease-cutter in the other 12, providing consumers with one product that does the work of multiple products in the convenience of a single unit-dose packet (FIG. 1).
The cold-water-soluble film inner packets containing the automatic dishwasher product provide the cleaning benefits of both a powdered detergent and a liquid grease cutter, encapsulated in a single, easy-to-use premeasured dose. Thus, existing water-soluble film technology has moved a step further in packaging powder and liquid together.
MonoSol provides film rollstock for the packet, a customized cast-copolymer film based on DuPont's ELVANOL® polyvinyl alcohol (PVOH) and MonoSol's M-8630, the latter of which was modified for P&G's requirements, including Kosher certification. The film itself dissolves completely in the dishwasher, without leaving residue or waste behind.
Precisely how the water-soluble, biodegradable packets can contain both a powder and a liquid without dissolving is the main reason the ACTIONPACS™ won a gold award in DuPont's annual packaging competition for their dual-purpose functionality and packaging ingenuity. P&G itself is secretive about the product, and will only say it manufactures the dual-phase ACTIONPACS™ at an undisclosed plant in the U.S. using three webs of identical MonoSol water-soluble film rolls and a horizontal form/fill/seal machine that uses standard sealing technology.
MonoSol uses what it calls a solution-casting process to produce the filmstock for the ACTIONPACS™. Completely transparent, the packets allow the CASCADE brand's white, powdered detergent and bright blue liquid grease cutter to show through, which adds sales appeal and invites inspection. The combination of cleaners starts to dissolve as soon as the dishwasher begins its wash cycle.
In this case, the technology goes a step further in the challenge of using the film in packaging applications for a commercial product like this one. Several years ago, MonoSol was asked to conduct studies to find a water-soluble film package that could contain liquids. Today, MonoSol has a group of products that can successfully be used to package liquids including homecare detergents and cleaners and dish and laundry detergents. So while the use of water-soluble packaging film isn't new, MonoSol has managed to successfully package products in their water-soluble materials, including agrochemicals, detergents and some industrial chemicals.
One challenge with the P&G application was to ensure compatibility between the water-soluble film and the two products—the composition of the powder and the liquid are very different, but MonoSol was able to meet the challenge. Everything from solubility and compatibility to machinability and mechanical properties as well as the cost of the film were important.
Several issues existed and had to be overcome during the development of P&G's ACTIONPACS™, including chemical compatibility of the product, the value-in-use of the packaging and the difficult handling conditions of the film (given its variability in different heat and humidity conditions). At the time of development, there were single-phase, water-soluble products on the market but no two-phase water-soluble products. A new process had to be developed to produce the products.
One remaining challenge related to the production of two-phase water-soluble products involves the recovery of off-spec production runs for the purpose of reusing packaged ingredients.